Polypropylene, Silicone Imported Positive-pressure flow for vacuum-free feeding that is similar to breastfeeding Reduces feeding problems like colic, spit-up, burping and gas Vent system that removes air from milk maintains essential vitamins such as C, A and E Helps prevent fluid in the ear BPA, PVC, lead and phthalate free Positive-pressure flow for vacuum-free feeding that is similar to breastfeeding Reduces feeding problems like colic, spit-up, burping and gas Vent system that removes air from milk maintains essential vitamins such as C, A and E Helps prevent fluid in the ear BPA, PVC, lead and phthalate freeDr. Browns